An integrated passive device (IPD) is a passive electrical component that contains one or more passive electrical circuit element(s), such as an inductor, capacitor, resistor or some series and parallel combination of these elements. An IPD does not include “active” circuit devices such as transistors, as an IPD with transistors would be more conventionally described as an integrated circuit (IC).
The function of an IPD is generally to bring the circuit elements available on the IPD in electrical communication with a corresponding IC. In a system employing an IPD, the electrical components present on the IPD would typically not be available on the IC substrates for any number of reasons, such as convenience, cost or availability. The rationale for these design decisions may be because designers determined that certain passive devices are necessary to achieve the desired circuit function, but it would be too expensive to include these passive devices on the same CMOS die as the microprocessor, as this die would likely use leading edge CMOS fabrication processes (such as the 7 nm Fin-Fet transistor process), which substantially increase the cost of the IC. Inclusion of the thin-film magnetic inductors on the IC substrate would compound the process complexity and consequently impact manufacturing yield and cost.
It would be desirable to have an IPD with improved functionality. It would also be desirable to improve the performance of the IPD and IC by locating them as close as possible to one another.